Current adjusting method and device for longitudinal differential protection of controllable phase-shifting transformer

Abstract

The invention discloses a current adjusting method and device for longitudinal differential protection of a controllable phase-shifting transformer, and the method comprises the steps: calculating a rated voltage coefficient at a gear-shifting side according to the actual gear information of a tap switch of a voltage-regulating transformer in the phase-shifting transformer, and calculating the rated current of each side of the voltage-regulating transformer at the current gear through the rated voltage coefficient, calculating the corrected rated current of each side of the voltage regulating transformer at the current gear according to the rated current of each side of the voltage regulating transformer at the current gear, and determining the adjusting current of each side of the voltage regulating transformer by using the corrected rated current and the secondary current sampling value of each side of the voltage regulating transformer; and calculating a longitudinal differential protection differential current according to the adjusting current of each side of the regulating transformer. According to the method disclosed by the invention, the longitudinal difference current calculation can be adaptively adjusted according to the gear information of actual operation, the abnormal condition of the difference current caused by the change of the gear information is prevented, and the reliability of the differential protection of the controllable phase-shifting transformer is improved.

Description

Technical Field

[0001] The present invention relates to the field of relay protection of electric power systems, and in particular to a current adjustment method and device for longitudinal differential protection of a controllable phase-shifting transformer. Background Art

[0002] The controllable phase-shifting transformer can flexibly adjust the voltage phase through the control of the tap changer to achieve system active power regulation. It is a more economical power flow control equipment. The voltage regulating transformer is an important part of the phase-shifting transformer, and its main function is to achieve voltage regulation. For common transformers with taps, when the taps are offset from the rated voltage, the rated voltage parameters in the relay protection device cannot be adaptively adjusted, resulting in differential current in the differential protection calculation. This tap has a small offset range and a small differential current amplitude. The braking characteristics of the differential protection can usually be used to prevent misoperation of the protection. The voltage regulating transformer in the phase-shifting transformer can not only be adjusted from 0 gear to full gear, but also can be adjusted from 0 gear to full gear with reverse polarity. When using fixed rated voltage parameters, the differential current calculated by the differential protection at different gears has a large deviation, the ratio braking characteristics cannot reliably brake the protection, and the transformer protection has the risk of misoperation. Summary of the invention

[0003] The object of the present invention is to provide a current adjustment method and device for longitudinal differential protection of a controllable phase-shifting transformer, so as to solve the problem that the longitudinal differential calculation of the voltage regulating transformer is affected by the gear position of the tap changer.

[0004] In order to achieve the above objectives, the solution of this application is:

[0005] According to the first aspect of the present application, a current adjustment method for longitudinal differential protection of a controllable phase-shifting transformer is proposed, comprising:

[0006] According to the parameters of the controllable phase-shifting transformer equipment, the operable gear of the voltage-regulating transformer in the controllable phase-shifting transformer, the rated voltage at each gear on the gear-regulating side, and the rated voltage on the non-gear-regulating side are obtained;

[0007] Receive the current gear position m of the voltage regulating transformer and obtain the secondary current sampling values ​​on each side of the voltage regulating transformer;

[0008] According to the rated voltage of the current m-gear position on the gear adjustment side, the rated voltage coefficient at the m-gear position on the gear adjustment side is calculated;

[0009] Calculate the rated current of the non-shifting side and the rated current of the shifting side at the m-shift position according to the rated voltage coefficient of the shifting side at the m-shift position, the rated voltage of the shifting side at the forward highest shift position M, and the rated voltage of the non-shifting side;

[0010] Calculate the corrected rated current of each side of the voltage regulating transformer at the m-gear position on the gear-shifting side according to the rated current on the non-gear-shifting side and the rated current on the gear-shifting side at the m-gear position;

[0011] Determine the adjustment current on each side of the voltage regulating transformer according to the corrected rated current on each side of the voltage regulating transformer at the current m gear and the secondary current sampling value on each side of the voltage regulating transformer;

[0012] The longitudinal differential protection differential current is calculated based on the adjustment current on each side of the voltage regulating transformer.

[0013] According to some embodiments, obtaining the operable gear of the voltage regulating transformer in the controllable phase-shifting transformer, the rated voltage at each gear on the gear-regulating side, and the rated voltage on the non-gear-regulating side according to the controllable phase-shifting transformer equipment parameters specifically includes:

[0014] The range of the gear position p of the voltage regulating transformer is: p∈[-M,M], where p is an integer. When p is less than 0, it is the reverse gear position; when p is greater than 0, it is the forward gear position; when p is equal to 0, it is the middle gear position; M is the highest forward gear position; and -M is the highest reverse gear position;

[0015] Get the rated voltage of the non-adjusting side of the voltage-regulating transformer and record it as U hM The rated voltage of the gear-shifting side in gear position p is recorded as U lp .

[0016] According to some embodiments, the rated voltage coefficient at the shift side m position is calculated as follows:

[0017]

[0018] Among them, k m is the rated voltage coefficient of the gear-shifting side in gear m, U lM is the rated voltage of the gear shifting side in the forward highest gear position M, U lm It is the rated voltage of the gear-shifting side in the M gear.

[0019] According to some embodiments, the calculation of the rated current of the non-shifting side and the rated current of the shifting side at the m-shift position according to the rated voltage coefficient of the shifting side at the m-shift position, the rated voltage of the shifting side at the forward highest shift position M-shift, and the rated voltage of the non-shifting side specifically includes:

[0020] According to the rated voltage of the non-shifting side, the rated current of the non-shifting side is calculated as follows:

[0021]

[0022] Among them, I h is the rated current of the non-shifting side, S is the rated capacity of the voltage-regulating transformer, U h It is the rated voltage of the non-shifting side;

[0023] According to the rated voltage of the gear-adjusting side in the forward highest gear position M, the rated current of the gear-adjusting side in the forward highest gear position M is calculated as follows:

[0024]

[0025] Among them, I lM is the rated current of the gear shifting side in the forward highest gear position M, U lM It is the rated voltage of the gear shifting side in the forward highest gear position M;

[0026] The rated current at the m-gear position is determined based on the rated current at the forward highest gear position M on the gear-shifting side and the rated voltage coefficient at the m-gear position; the calculation formula is:

[0027]

[0028] Among them, I lm is the rated current when the gear is in the M position, k m It is the rated voltage coefficient of the gear adjustment side in the M gear.

[0029] According to some embodiments, the corrected rated current of each side of the voltage regulating transformer at the m-gear position on the gear side is calculated based on the rated current on the non-gear side and the rated current on the gear side at the m-gear position, and the calculation formula is:

[0030]

[0031] Among them, I′ hm I′ is the corrected rated current of the non-shifting side when the shifting side is in the m position. lm is the corrected rated current when the gear is in the M position, μ m is the adjustment coefficient, μ m The value range is k m ~1, k m I is the rated voltage coefficient of the gear-shifting side in gear m; h is the rated current of the non-shifting side, I lm It is the rated current of the gear-shifting side in the M gear.

[0032] According to some embodiments, the calibrated rated current on each side of the voltage regulating transformer and the secondary current sampling value on each side of the voltage regulating transformer at the current m gear are used to determine the adjusted current on each side of the voltage regulating transformer, specifically:

[0033] Calculate the corrected secondary rated current on each side of the voltage regulating transformer as:

[0034]

[0035] Among them, I' 2hm is the corrected secondary rated current on the non-shift side, I' 2lmis the corrected secondary rated current on the gear shifting side, I′ hm I′ is the corrected rated current of the non-shifting side when the shifting side is in the m position. lm is the corrected rated current when the gear is in the M position, n h and n l are the CT ratios of the non-shifting side and the shifting side respectively;

[0036] Calculate the balance factor on each side of the transformer as:

[0037]

[0038] In the formula, K ph is the balance coefficient of the non-shifting side, K p l is the balance coefficient on the gear shifting side, I 2n_max =max(I′ 2hm ,I′ 2lm ), I 2n_min =min(I′ 2hm ,I′ 2lm ), when m>0, sgn(m)=1; when m<0, sgn(m)=-1; when m=0, sgn(m)=0;

[0039] Calculate the adjustment current on each side as:

[0040]

[0041] In the formula, I h_adj and I l_adj are the adjustment currents of the non-gear adjustment side and the gear adjustment side, I h_s and I l_s They are the secondary current sampling values ​​of the non-gear-adjusting side and the gear-adjusting side respectively.

[0042] According to some embodiments, the differential current calculation method is as follows:

[0043] I d =I h_adj +I l_adj

[0044] Among them, I d is the differential current, I h_adj and I l_adj They are the adjustment currents on the non-gear adjustment side and the gear adjustment side respectively.

[0045] According to the second aspect of the present application, a current adjustment device for longitudinal differential protection of a controllable phase-shifting transformer is proposed, comprising:

[0046] A parameter acquisition unit, used to acquire the operable gear of the voltage regulating transformer in the controllable phase-shifting transformer, the rated voltage at each gear on the gear-regulating side, and the rated voltage on the non-gear-regulating side according to the equipment parameters of the controllable phase-shifting transformer;

[0047] The sampling unit is used to receive the current gear position m of the voltage regulating transformer and obtain the secondary current sampling values ​​on each side of the voltage regulating transformer;

[0048] A rated voltage coefficient calculation unit, used to calculate the rated voltage coefficient of the gear adjustment side at the m gear position according to the rated voltage of the gear adjustment side at the current m gear position;

[0049] A rated current calculation unit, used for calculating the rated current of the non-shifting side and the rated current of the shifting side at the m-shift position according to the rated voltage coefficient of the shifting side at the m-shift position, the rated voltage of the shifting side at the forward highest shift position M, and the rated voltage of the non-shifting side;

[0050] A corrected rated current calculation unit, used for calculating the corrected rated current of each side of the voltage regulating transformer at the m-gear position on the gear side according to the rated current on the non-gear side and the rated current on the gear side at the m-gear position;

[0051] The adjustment current calculation unit is used to determine the adjustment current on each side of the voltage regulating transformer according to the corrected rated current on each side of the voltage regulating transformer and the secondary current sampling value on each side of the voltage regulating transformer at the current m gear;

[0052] The differential current calculation unit is used to calculate the longitudinal differential protection differential current according to the adjustment current on each side of the voltage regulating transformer.

[0053] According to a third aspect of the present application, an electronic device is proposed, comprising a processor and a memory, wherein the memory stores a program, and the program can be loaded by the processor to execute the current adjustment method of the longitudinal differential protection of the controllable phase-shifting transformer.

[0054] According to a fourth aspect of the present application, a computer-readable storage medium is proposed, storing a computer program, and when the computer program is executed by a processor, the current adjustment method for the longitudinal differential protection of the controllable phase-shifting transformer is implemented.

[0055] The beneficial effects of the present invention are as follows: by adopting the method described in the present invention, the corrected rated current on each side of the voltage-regulating transformer at the current gear is calculated according to the actual gear information of the tap switch of the voltage-regulating transformer in the phase-shifting transformer, and then the corrected rated current is used to perform differential protection calculation, thereby realizing adaptive adjustment of the longitudinal differential protection calculation, preventing abnormal differential current caused by changes in gear information, and improving the reliability of the differential protection of the controllable phase-shifting transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1A flow chart of a current adjustment method for longitudinal differential protection of a controllable phase-shifting transformer provided in an embodiment of the present application.

[0057] Figure 2 This is the structure of the voltage regulating transformer inside the phase-shifting transformer in the embodiment of the present application.

[0058] Figure 3 A flow chart of a method for calculating the rated current on each side of a voltage regulating transformer provided in an embodiment of the present application.

[0059] Figure 4 A flow chart of a method for calculating the adjustment current on each side of a voltage regulating transformer provided in an embodiment of the present application.

[0060] Figure 5 A schematic structural diagram of a current adjustment device for longitudinal differential protection of a controllable phase-shifting transformer provided in an embodiment of the present application.

[0061] Figure 6 A structural diagram of an electronic device provided for this application. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below based on the accompanying drawings and embodiments. It should be understood that the specific implementation described here is only used to explain the present invention and does not limit the present invention.

[0063] In order to make the voltage regulating transformer longitudinal differential calculation not be affected by the tap changer gear position, it is necessary to adaptively correct the rated current on each side of the voltage regulating transformer according to the received gear position information, and keep the calculated differential current balanced during normal operation and out-of-zone faults. In view of this, the embodiment of the present application proposes a current adjustment method for controllable phase-shifting transformer longitudinal differential protection, such as Figure 1 The steps shown include:

[0064] S100: According to the equipment parameters of the controllable phase-shifting transformer, the operable gear of the voltage-regulating transformer in the controllable phase-shifting transformer, the rated voltage at each gear on the gear-regulating side, and the rated voltage on the non-gear-regulating side are obtained.

[0065] The primary structure and parameters of the controllable phase-shifting transformer determine its gear adjustment range. Figure 2 As shown, the controllable phase-shifting transformer and the voltage-regulating transformer tap changer can be operated to gear p. The gear p of the voltage-regulating transformer has a value range of: p∈[-M,M], where p is an integer. When p is less than 0, it is the reverse gear, when p is greater than 0, it is the forward gear, and when p is equal to 0, it is the intermediate gear. M is the highest forward gear, and -M is the highest reverse gear. The rated voltage of the non-gear side of the voltage-regulating transformer is obtained and recorded as U hM The rated voltage of the gear-shifting side in gear position p is recorded as U lp .

[0066] S200: Receive the current gear position m of the voltage regulating transformer, and obtain the secondary current sampling values ​​on each side of the voltage regulating transformer.

[0067] Receive the gear information sent from the tap changer control device to obtain the current gear m of the voltage regulating transformer. Obtain the secondary current sampling value on each side of the voltage regulating transformer through the current transformer installed on each side of the voltage regulating transformer. The secondary current sampling value on the non-gear side is recorded as I h_s , the secondary current sampling value on the gear adjustment side is recorded as I l_s .

[0068] S300: Calculate the rated voltage coefficient of the gear adjustment side at the m gear position according to the rated voltage of the gear adjustment side at the current m gear position.

[0069] In some embodiments, the rated voltage coefficient at the m gear position on the gear adjustment side is calculated as follows:

[0070]

[0071] Among them, k m is the rated voltage coefficient of the gear-shifting side in gear m, U lM is the rated voltage of the gear shifting side in the forward highest gear position M, U lm is the rated voltage of the gear-adjusting side at gear m. When m = 0, the rated voltage of the gear-adjusting side is U lm =0, k m =0.

[0072] S400: Calculate the rated current of the non-shifting side and the rated current of the shifting side at the m-shift position according to the rated voltage coefficient of the shifting side at the m-shift position, the rated voltage of the shifting side at the forward highest shift position M, and the rated voltage of the non-shifting side.

[0073] In some embodiments, the calculation method of the rated current of the non-shift side and the rated current of the shift side at the m-shift position is as follows: Figure 3 The following steps are shown:

[0074] S401: Calculate the rated current of the non-shift side according to the rated voltage of the non-shift side. The calculation method is:

[0075]

[0076] Among them, I h is the rated current of the non-shifting side, S is the rated capacity of the voltage-regulating transformer, U h It is the rated voltage of the non-shifting side;

[0077] S402: Calculate the rated current of the gear adjustment side at the forward highest gear position M according to the rated voltage of the gear adjustment side at the forward highest gear position M. The calculation method is:

[0078]

[0079] Among them, I lM is the rated current of the gear shifting side in the forward highest gear position M, U lM It is the rated voltage of the gear shifting side in the forward highest gear position M;

[0080] S403: Determine the rated current at the m gear according to the rated current of the gear-adjusting side at the forward highest gear M gear and the rated voltage coefficient at the m gear; the calculation formula is:

[0081]

[0082] Among them, I lm is the rated current when the gear is in the M position, k m It is the rated voltage coefficient of the gear adjustment side in the M gear.

[0083] S500: Calculate the corrected rated current of each side of the voltage regulating transformer at the m-gear position on the gear-shifting side according to the rated current on the non-gear-shifting side and the rated current on the gear-shifting side at the m-gear position.

[0084] In some embodiments, the calculation formula for the corrected rated current of each side of the voltage regulating transformer at the mth gear on the gear regulating side is:

[0085]

[0086] Among them, I′ hm I′ is the corrected rated current of the non-shifting side when the shifting side is in the m position. lm is the corrected rated current when the gear is in the M position, μ m is the adjustment coefficient, μ m The value range is k m ~1, k m I is the rated voltage coefficient of the gear-shifting side in gear m; h is the rated current of the non-shifting side, I lm It is the rated current of the gear-shifting side in the M gear.

[0087] S600: Determine the adjustment current on each side of the voltage regulating transformer according to the corrected rated current on each side of the voltage regulating transformer at the current m gear and the secondary current sampling value on each side of the voltage regulating transformer.

[0088] In some embodiments, the method for determining the adjustment current of each side of the voltage regulating transformer is as follows: Figure 4 The steps shown include:

[0089] S601: Calculate the corrected secondary rated current on each side of the voltage regulating transformer as:

[0090]

[0091] Among them, I' 2hm is the corrected secondary rated current on the non-shift side, I' 2lm is the corrected secondary rated current on the gear shifting side, I′ hm I′ is the corrected rated current of the non-shifting side when the shifting side is in the m position. lm is the corrected rated current when the gear is in the M position on the gear shifting side, n h and n l are the CT ratios of the non-shifting side and the shifting side respectively;

[0092] S602: Calculate the balance coefficient of each side of the transformer:

[0093]

[0094] In the formula, K ph is the balance coefficient of the non-shifting side, K p l is the balance coefficient on the gear shifting side, I 2n_max =max(I′ 2hm ,I′ 2lm ), I 2n_min =min(I′ 2hm ,I′ 2lm ), when m>0, sgn(m)=1; when m<0, sgn(m)=-1; when m=0, sgn(m)=0;

[0095] S603: Calculate the adjustment current on each side as:

[0096]

[0097] In the formula, I h_adj and I l_adj are the adjustment currents of the non-gear adjustment side and the gear adjustment side, I h_s and I l_s They are the secondary current sampling values ​​of the non-gear-adjusting side and the gear-adjusting side respectively.

[0098] S700: Calculates the longitudinal differential protection differential current based on the adjustment current on each side of the voltage regulating transformer.

[0099] In some embodiments, the differential current calculation method is as follows:

[0100] I d =I h_adj +I l_adj

[0101] Among them, I d is the differential current, I h_adj and I l_adj They are the adjustment currents on the non-gear adjustment side and the gear adjustment side respectively.

[0102] By adopting the technical solution of the present invention, the corrected rated current on each side of the voltage-regulating transformer at the current gear is calculated according to the actual gear information of the tap changer of the voltage-regulating transformer in the phase-shifting transformer, and the corrected rated current is then used to perform differential protection calculation, thereby realizing adaptive adjustment of the longitudinal differential protection calculation, preventing abnormal differential current caused by changes in gear information, and improving the reliability of differential protection of the controllable phase-shifting transformer.

[0103] Figure 5 The current adjustment device 800 for longitudinal differential protection of a controllable phase-shifting transformer provided in an embodiment of the present application is shown, comprising: a parameter acquisition unit 801, a sampling unit 802, a rated voltage coefficient calculation unit 803, a rated current calculation unit 804, a corrected rated current calculation unit 805, an adjustment current calculation unit 806 and a differential current calculation unit 807. Among them:

[0104] The parameter acquisition unit 801 is used to obtain the operable gears of the voltage regulating transformer in the controllable phase-shifting transformer, the rated voltages at each gear on the regulating side, and the rated voltage on the non-regulating side according to the equipment parameters of the controllable phase-shifting transformer.

[0105] The sampling unit 802 is used to receive the current gear position m of the voltage regulating transformer and obtain the secondary current sampling values ​​on each side of the voltage regulating transformer.

[0106] The rated voltage coefficient calculation unit 803 is used to calculate the rated voltage coefficient of the gear adjustment side at the m gear position according to the rated voltage of the gear adjustment side at the current m gear position.

[0107] The rated current calculation unit 804 is used to calculate the rated current of the non-shifting side and the rated current of the shifting side at the m gear position according to the rated voltage coefficient of the shifting side at the m gear position, the rated voltage of the shifting side at the forward highest gear position M, and the rated voltage of the non-shifting side.

[0108] The corrected rated current calculation unit 805 is used to calculate the corrected rated current of each side of the voltage regulating transformer at the mth gear on the gear side according to the rated current on the non-gear side and the rated current on the mth gear on the gear side.

[0109] The adjustment current calculation unit 806 is used to determine the adjustment current on each side of the voltage regulating transformer according to the corrected rated current on each side of the voltage regulating transformer and the secondary current sampling value on each side of the voltage regulating transformer at the current m gear.

[0110] The differential current calculation unit 807 is used to calculate the longitudinal differential protection differential current according to the adjustment currents on each side of the voltage regulating transformer.

[0111] A current adjustment device 800 for longitudinal differential protection of a controllable phase-shifting transformer in the present application performs functions similar to those of the aforementioned method. For details, please refer to the previous description, which will not be repeated here.

[0112] Figure 6 The structure diagram of an electronic device provided by the present application is shown. It includes a processor and a memory. The memory stores computer instructions. When the computer instructions are executed by the processor, the processor executes the computer instructions to achieve the following. Figure 1 The method and refinement scheme shown.

[0113] It should be understood that the above device embodiments are only illustrative, and the device disclosed in the present invention can also be implemented in other ways. For example, the division of units / modules described in the above embodiments is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units, modules or components can be combined, or can be integrated into another system, or some features can be ignored or not executed.

[0114] In addition, unless otherwise specified, each functional unit / module in each embodiment of the present invention may be integrated into one unit / module, each unit / module may exist physically separately, or two or more units / modules may be integrated together. The above-mentioned integrated unit / module may be implemented in the form of hardware or in the form of a software program module.

[0115] If the integrated unit / module is implemented in the form of hardware, the hardware may be a digital circuit, an analog circuit, etc. The physical implementation of the hardware structure includes but is not limited to transistors, memristors, etc. If not otherwise specified, the processor or chip may be any appropriate hardware processor, such as a CPU, a GPU, an FPGA, a DSP, an ASIC, etc. If not otherwise specified, the on-chip cache, the off-chip memory, and the memory may be any appropriate magnetic storage medium or magneto-optical storage medium, such as a resistive random access memory RRAM (Resistive Random Access Memory), a dynamic random access memory DRAM (Dynamic Random Access Memory), a static random access memory SRAM (Static Random-Access Memory), an enhanced dynamic random access memory EDRAM (Enhanced Dynamic Random Access Memory), a high-bandwidth memory HBM (High-Bandwidth Memory), a hybrid memory cube HMC (Hybrid Memory Cube), etc.

[0116] If the integrated unit / module is implemented in the form of a software program module and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a memory and includes several instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present disclosure. The aforementioned memory includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0117] The present application also provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the processor executes the following Figure 1 The method and refinement scheme shown.

[0118] It should be clearly understood that the present application describes how to form and use specific examples, but the present application is not limited to any details of these examples. On the contrary, based on the teaching of the content disclosed in the present application, these principles can be applied to many other embodiments.

[0119] In addition, it should be noted that the above figures are only schematic illustrations of the processes included in the method according to the exemplary embodiments of the present application, and are not intended to be limiting. It is easy to understand that the processes shown in the above figures do not indicate or limit the time sequence of these processes. In addition, it is also easy to understand that these processes can be performed synchronously or asynchronously, for example, in multiple modules.

[0120] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A current adjustment method for longitudinal differential protection of a controllable phase-shifting transformer, It is characterized in that include: According to the parameters of the controllable phase-shifting transformer equipment, the operable gear of the voltage-regulating transformer in the controllable phase-shifting transformer, the rated voltage at each gear on the gear-regulating side, and the rated voltage on the non-gear-regulating side are obtained; Receive the current gear position m of the voltage regulating transformer and obtain the secondary current sampling values ​​on each side of the voltage regulating transformer; According to the rated voltage of the current m-gear position on the gear adjustment side, the rated voltage coefficient of the gear adjustment side at the m-gear position is calculated; Calculate the rated current of the non-shifting side and the rated current of the shifting side at the m-shift position according to the rated voltage coefficient of the shifting side at the m-shift position, the rated voltage of the shifting side at the forward highest shift position M, and the rated voltage of the non-shifting side; Calculate the corrected rated current of each side of the voltage regulating transformer at the m-gear position on the gear-shifting side according to the rated current on the non-gear-shifting side and the rated current on the gear-shifting side at the m-gear position; Determine the adjustment current on each side of the voltage regulating transformer according to the corrected rated current on each side of the voltage regulating transformer at the current m gear and the secondary current sampling value on each side of the voltage regulating transformer; The longitudinal differential protection differential current is calculated based on the adjustment current on each side of the voltage regulating transformer.

2. The method according to claim 1, It is characterized in that The step of obtaining the operable gear of the voltage regulating transformer in the controllable phase-shifting transformer, the rated voltage at each gear on the regulating side, and the rated voltage on the non-regulating side according to the controllable phase-shifting transformer equipment parameters specifically includes: The range of the gear position p of the voltage regulating transformer is: p∈[-M,M], where p is an integer. When p is less than 0, it is the reverse gear position; when p is greater than 0, it is the forward gear position; when p is equal to 0, it is the middle gear position; M is the highest forward gear position; and -M is the highest reverse gear position; Get the rated voltage of the non-adjusting side of the voltage-regulating transformer and record it as U hM The rated voltage of the gear-shifting side in gear position p is recorded as U lp .

3. The method according to claim 1, It is characterized in that The calculation method of the rated voltage coefficient at the m gear position on the gear shifting side is: Among them, k m is the rated voltage coefficient of the gear-shifting side in gear m, U lM is the rated voltage of the gear shifting side in the forward highest gear position M, U lm It is the rated voltage of the gear-shifting side in the M gear.

4. The method according to claim 1, It is characterized in that The step of calculating the rated current of the non-shifting side and the rated current of the shifting side at the m-shift position according to the rated voltage coefficient of the shifting side at the m-shift position, the rated voltage of the shifting side at the forward highest shift position M, and the rated voltage of the non-shifting side specifically includes: According to the rated voltage of the non-shifting side, the rated current of the non-shifting side is calculated as follows: Among them, I h is the rated current of the non-shifting side, S is the rated capacity of the voltage-regulating transformer, U h It is the rated voltage of the non-shifting side; According to the rated voltage of the gear-adjusting side in the forward highest gear position M, the rated current of the gear-adjusting side in the forward highest gear position M is calculated as follows: Among them, I lM is the rated current of the gear shifting side in the forward highest gear position M, U lM It is the rated voltage of the gear shifting side in the forward highest gear position M; The rated current at the m-gear position is determined based on the rated current at the forward highest gear position M on the gear-shifting side and the rated voltage coefficient at the m-gear position; the calculation formula is: Among them, I lm is the rated current when the gear is in the M position, k m It is the rated voltage coefficient of the gear adjustment side in the M gear.

5. The method according to claim 1, It is characterized in that The corrected rated current of each side of the voltage regulating transformer at the m-gear position on the gear-shifting side is calculated according to the rated current on the non-gear-shifting side and the rated current at the m-gear position on the gear-shifting side, and the calculation formula is: Among them, I′ hm I′ is the corrected rated current of the non-shifting side when the shifting side is in the m position. lm is the corrected rated current when the gear is in the M position, μ m is the adjustment coefficient, μ m The value range is k m ~1, k m I is the rated voltage coefficient of the gear-shifting side in gear m; h is the rated current of the non-shifting side, I lm It is the rated current of the gear adjustment side in the M gear.

6. The method according to claim 1, It is characterized in that The calibrated rated current on each side of the voltage regulating transformer at the current m gear and the secondary current sampling value on each side of the voltage regulating transformer are used to determine the adjusted current on each side of the voltage regulating transformer, specifically: Calculate the corrected secondary rated current on each side of the voltage regulating transformer as: Among them, I' 2hm is the corrected secondary rated current on the non-shift side, I' 2lm is the corrected secondary rated current on the gear shifting side, I′ hm I′ is the corrected rated current of the non-shifting side when the shifting side is in the m position. lm is the corrected rated current when the gear is in the M position on the gear shifting side, n h and n l are the CT ratios of the non-shifting side and the shifting side respectively; Calculate the balance factor on each side of the transformer as: In the formula, K ph is the balance coefficient of the non-shifting side, K pl is the balance coefficient on the gear shifting side, I 2n_max =max(I′ 2hm ,I′ 2lm ), I 2n_min =min(I′ 2hm ,I′ 2lm ), when m>0, sgn(m)=1; when m<0, sgn(m)=-1; when m=0, sgn(m)=0; Calculate the adjustment current on each side as: In the formula, I h_adj and I l_adj are the adjustment currents of the non-gear adjustment side and the gear adjustment side, I h_s and I l_s They are the secondary current sampling values ​​of the non-gear-adjusting side and the gear-adjusting side respectively.

7. The method according to claim 1, It is characterized in that The differential current calculation method is as follows: I d =I h_adj +I l_adj Among them, I d is the differential current, I h_adj and I l_adj They are the adjustment currents on the non-gear adjustment side and the gear adjustment side respectively.

8. A current adjustment device for longitudinal differential protection of a controllable phase-shifting transformer, It is characterized in that include: A parameter acquisition unit, used to acquire the operable gear of the voltage regulating transformer in the controllable phase-shifting transformer, the rated voltage at each gear on the gear-regulating side, and the rated voltage on the non-gear-regulating side according to the equipment parameters of the controllable phase-shifting transformer; The sampling unit is used to receive the current gear position m of the voltage regulating transformer and obtain the secondary current sampling values ​​on each side of the voltage regulating transformer; A rated voltage coefficient calculation unit, used to calculate the rated voltage coefficient of the gear adjustment side at the m gear position according to the rated voltage of the gear adjustment side at the current m gear position; A rated current calculation unit, used for calculating the rated current of the non-shifting side and the rated current of the shifting side at the m-shift position according to the rated voltage coefficient of the shifting side at the m-shift position, the rated voltage of the shifting side at the forward highest shift position M, and the rated voltage of the non-shifting side; A corrected rated current calculation unit, used for calculating the corrected rated current of each side of the voltage regulating transformer at the m-gear position on the gear side according to the rated current on the non-gear side and the rated current on the gear side at the m-gear position; an adjustment current calculation unit, for determining the adjustment current on each side of the voltage regulating transformer according to the corrected rated current on each side of the voltage regulating transformer and the secondary current sampling value on each side of the voltage regulating transformer at the current m gear; and The differential current calculation unit is used to calculate the longitudinal differential protection differential current according to the adjustment current on each side of the voltage regulating transformer.

9. An electronic device, Features: The method comprises a processor and a memory, wherein the memory stores a program, and the program can be loaded by the processor to execute the method as claimed in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, It is characterized in that When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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